Fix minor linting inconsitency (my clang-format is too new?)

lib/structs/user_interactive.cpp

@@ -62,7 +62,7 @@ struct overloaded : Ts...
         using Ts::operator()...;
 };
 template<class... Ts>
-overloaded(Ts...)->overloaded<Ts...>;
+overloaded(Ts...) -> overloaded<Ts...>;
 }
 
 namespace auth {